From 6f0b2c696ca340cc2da381fe693fda3f8fdb2149 Mon Sep 17 00:00:00 2001 From: Yadwinder Singh Brar Date: Mon, 11 Jun 2012 17:41:08 +0530 Subject: regulator: Add ramp_delay configuration to constraints For some hardwares ramp_delay for BUCKs is a configurable parameter which can be configured through DT or board file.This patch adds ramp_delay to regulator constraints and allow user to configure it for regulators which supports this feature, through DT or board file. It will provide two ways of setting the ramp_delay for a regulator: First, by setting it as constraints in board file(for configurable regulators) and set_machine_constraints() will take care of setting it on hardware by calling(the provided) .set_ramp_delay() operation(callback). Second, by setting it as data in regulator_desc(as fixed/default ramp_delay rate) for a regulator in driver. regulator_set_voltage_time_sel() will give preference to constraints->ramp_delay while reading ramp_delay rate for regulator. Similarly users should also take care accordingly while refering ramp_delay rate(in case of implementing their private .set_voltage_time_sel() callbacks for different regulators). [Rewrote subject for 80 columns -- broonie] Signed-off-by: Yadwinder Singh Brar Signed-off-by: Mark Brown --- .../devicetree/bindings/regulator/regulator.txt | 1 + drivers/regulator/core.c | 23 ++++++++++++++++++---- drivers/regulator/of_regulator.c | 6 +++++- include/linux/regulator/driver.h | 3 +++ include/linux/regulator/machine.h | 3 +++ 5 files changed, 31 insertions(+), 5 deletions(-) diff --git a/Documentation/devicetree/bindings/regulator/regulator.txt b/Documentation/devicetree/bindings/regulator/regulator.txt index 5b7a408acdaa..d0a7b1296a36 100644 --- a/Documentation/devicetree/bindings/regulator/regulator.txt +++ b/Documentation/devicetree/bindings/regulator/regulator.txt @@ -10,6 +10,7 @@ Optional properties: - regulator-always-on: boolean, regulator should never be disabled - regulator-boot-on: bootloader/firmware enabled regulator - -supply: phandle to the parent supply/regulator node +- regulator-ramp-delay: ramp delay for regulator(in mV/uS) Example: diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 6ffca9b32388..b615ae6606db 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -967,6 +967,14 @@ static int set_machine_constraints(struct regulator_dev *rdev, } } + if (rdev->constraints->ramp_delay && ops->set_ramp_delay) { + ret = ops->set_ramp_delay(rdev, rdev->constraints->ramp_delay); + if (ret < 0) { + rdev_err(rdev, "failed to set ramp_delay\n"); + goto out; + } + } + print_constraints(rdev); return 0; out: @@ -2296,10 +2304,17 @@ int regulator_set_voltage_time_sel(struct regulator_dev *rdev, unsigned int old_selector, unsigned int new_selector) { - if (rdev->desc->ramp_delay && rdev->desc->uV_step) - return DIV_ROUND_UP(rdev->desc->uV_step * - abs(new_selector - old_selector), - rdev->desc->ramp_delay * 1000); + if (rdev->desc->uV_step) { + if (rdev->constraints->ramp_delay) + return DIV_ROUND_UP(rdev->desc->uV_step * + abs(new_selector - old_selector), + rdev->constraints->ramp_delay * 1000); + if (rdev->desc->ramp_delay) + return DIV_ROUND_UP(rdev->desc->uV_step * + abs(new_selector - old_selector), + rdev->desc->ramp_delay * 1000); + rdev_warn(rdev, "ramp_delay not set\n"); + } return 0; } diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c index 56593b75168a..e2a731079066 100644 --- a/drivers/regulator/of_regulator.c +++ b/drivers/regulator/of_regulator.c @@ -20,7 +20,7 @@ static void of_get_regulation_constraints(struct device_node *np, struct regulator_init_data **init_data) { const __be32 *min_uV, *max_uV, *uV_offset; - const __be32 *min_uA, *max_uA; + const __be32 *min_uA, *max_uA, *ramp_delay; struct regulation_constraints *constraints = &(*init_data)->constraints; constraints->name = of_get_property(np, "regulator-name", NULL); @@ -60,6 +60,10 @@ static void of_get_regulation_constraints(struct device_node *np, constraints->always_on = true; else /* status change should be possible if not always on. */ constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS; + + ramp_delay = of_get_property(np, "regulator-ramp-delay", NULL); + if (ramp_delay) + constraints->min_uV = be32_to_cpu(*ramp_delay); } /** diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h index ae5c25379237..ddc155d262da 100644 --- a/include/linux/regulator/driver.h +++ b/include/linux/regulator/driver.h @@ -67,6 +67,8 @@ enum regulator_status { * * @enable_time: Time taken for the regulator voltage output voltage to * stabilise after being enabled, in microseconds. + * @set_ramp_delay: Set the ramp delay for the regulator. The driver should + * select ramp delay equal to or less than(closest) ramp_delay. * @set_voltage_time_sel: Time taken for the regulator voltage output voltage * to stabilise after being set to a new value, in microseconds. * The function provides the from and to voltage selector, the @@ -113,6 +115,7 @@ struct regulator_ops { /* Time taken to enable or set voltage on the regulator */ int (*enable_time) (struct regulator_dev *); + int (*set_ramp_delay) (struct regulator_dev *, int ramp_delay); int (*set_voltage_time_sel) (struct regulator_dev *, unsigned int old_selector, unsigned int new_selector); diff --git a/include/linux/regulator/machine.h b/include/linux/regulator/machine.h index b02108446be7..5f37ad3cc172 100644 --- a/include/linux/regulator/machine.h +++ b/include/linux/regulator/machine.h @@ -92,6 +92,7 @@ struct regulator_state { * mode. * @initial_state: Suspend state to set by default. * @initial_mode: Mode to set at startup. + * @ramp_delay: Time to settle down after voltage change (unit: mV/us) */ struct regulation_constraints { @@ -125,6 +126,8 @@ struct regulation_constraints { /* mode to set on startup */ unsigned int initial_mode; + unsigned int ramp_delay; + /* constraint flags */ unsigned always_on:1; /* regulator never off when system is on */ unsigned boot_on:1; /* bootloader/firmware enabled regulator */ -- cgit v1.2.3-59-g8ed1b